Robotic systems for assisting in a number of medical procedures have been proposed, including neurosurgical, laparoscopic, and orthopedic procedures. When performing robotically assisted surgery, (for example, total hip replacement when cutting a cavity into a patient's femur bone for the insertion of an artificial hip joint therein), it is very important to balance the weight of a moving extended arm so the system does not tip. Various types of robots use counterbalance weights, gas springs and mechanical springs to help achieve this balance.
It is also important to consider the robot's vertical axis of motion, for example a robot having a vertical axis of motion that does not need a separate high precision Z axis at the robot wrist and makes the robot arm easier to reposition manually when necessary. For example, some existing arm designs have two separate vertical (Z-axis) actuators: a high precision drive at the wrist, and a lower precision lifting column actuator (with high moment load rating) at the base of the robot arm's vertical pedestal. The base column is used for gross positioning, and the wrist Z is used for fine positioning. In the event that the vertical position of the robotic arm must be manually adjusted, the user must reach up and release a brake lever, causing the wrist Z to drop freely under its own weight (unless hand-held in place).
Accordingly, it has been desirable to attempt to counter balance the robot's vertical axis of motion while making the robot arm easier to reposition manually when necessary.
The ORTHODOC presurgical planning workstation and the ROBODOC robotic surgical system are described in a number of references, including the following: (1) Kazanzides, P., Zuhars, J., Mittelstadt, B. D., Taylor, R. H.: “Force Sensing and Control for a Surgical Robot,” Proc. IEEE Conference. on Robotics & Automation, Pages 612-616, Nice, France, May 1992. (2) Kazanzides, P., Zuhars, J., Mittelstadt, B. D., Williamson, B., Cain, P., Smith, F., Rose, L., Mustis, B.: “Architecture of a Surgical Robot,” Proc. IEEE Conference. on Systems, Man, and Cybernetics, Chicago, Ill., Pages 1624-1629, October, 1992. (3) Paul, H. A., Bargar, W. L., Mittelstadt, B., Musits, B., Taylor, R. H., Kazanzides, P., Zuhars, J., Williamson, B., Hanson, W.: “Development of a Surgical Robot For Cementless Total Hip Arthroplasty,” Clinical Orthopaedics, Volume 285, Pages 57-66, December 1992. (4) Kazanzides, P., Mittelstadt, B. D., Zuhars, J., Cain, P., Paul, H. A., “Surgical and Industrial Robots: Comparison and Case Study,” Proc. International Robots and Vision Automation Conference, Pages 1019-1026, Detroit, Mich., April 1993. (5) Mittelstadt, B., Kazanzides, P., Zuhars, J., Williamson, B., Pettit, R., Cain, P., Kloth, D., Rose, L., Musits, B.: “Development of a surgical robot for cementless total hip replacement,” Robotica, Volume 11, Pages 553-560, 1993. (6) Mittelstadt B., Kazanzides, P., Zuhars, J., Cain, P., Williamson, B.: “Robotic surgery: Achieving predictable results in an unpredictable environment,” Proc. Sixth International Conference on Advanced Robotics, Pages 367-372, Tokyo, November, 1993. (7) Cain, P., Kazanzides, P., Zuhars, J., Mittelstadt, B., Paul, H.: “Safety Considerations in a Surgical Robot,” Biomedical Sciences Instrumentation, Volume 29, Pages 291-294, San Antonio, Tex., April 1993. (8) Mittelstadt, B. D., Kazanzides, P., Zuhars, J., Williamson, B., Cain, P., Smith, F. Bargar, W.: “The Evolution of A Surgical Robot From Prototype to Human Clinical Use,” in Proc. First International Symposium on Medical Robotics and Computer Assisted Surgery, Volume I, Pages 36-41, Pittsburgh, Pa., September 1994.
Other publications which describe image registration in robotic surgical and other procedures include the following: (9) Grimson, W. E. L., Lozano-Perez, T., Wells III, W. M., Ettinger, G. J., White, S. J., Kikinis, R.: “Automated Registration for Enhanced Reality Visualization in Surgery,” Proceedings of the First International Symposium on Medical Robotics and Computer Assisted Surgery, Volume I, Sessions I-III, Pages 82-89, Pittsburgh, Pa., Sep. 22-24, 1995. (10) Nolte, L. P., Zamorano, L. J., Jiang, Z., Wang, Q., Langlotz, F., Arm, E., Visarius, H.: “A Novel Approach to Computer Assisted Spine Surgery,” Proceedings of the First International Symposium on Medical Robotics and Computer Assisted Surgery, Volume II, Session IV, Pages 323-328, Pittsburgh, Pa., Sep. 22-24, 1994. (11) Lavallee, S., Sautot, P., Troccaz, J., Cinquin, P., Merloz, P.: “Computer Assisted Spine Surgery: a technique for accurate transpedicular screw fixation using CT data and a 3-D optical localizer,” Proceedings of the First International Symposium on Medical Robotics and Computer Assisted Surgery, Volume II, Session IV, Pages 315-321, Pittsburgh, Pa., Sep. 22-24, 1994. (12) Potamianos, P., Davies, B. L., Hibberd, R. D.: “Intra-Operative Imaging Guidance For Keyhole Surgery Methodology and Calibration,” Proceedings of the First International Symposium on Medical Robotics and Computer Assisted Surgery, Volume I, Sessions I-III, Pages 98-104, Pittsburgh, Pa., Sep. 22-24, 1994. (13) Simon, D. A., Hebert, M., Kanade, T.: “Techniques for Fast and Accurate Intra-Surgical Registration,” Proceedings of the First International Symposium on Medical Robotics and Computer Assisted Surgery, Volume I, Sessions I-III, Pages 90-97, Pittsburgh, Pa., Sep. 22-24, 1995. (14) Peria, O., Francois-Joubert, A., Lavallee, S., Champleboux, G., Cinquin, P., Grand, S.: “Accurate Registration of SPECT and MR brain images of patients suffering from epilepsy or tumor,” Proceedings of the First International Symposium on Medical Robotics and Computer Assisted Surgery, Volume II, Session IV, Pages 58-62, Pittsburgh, Pa., Sep. 22-24, 1995. (15) Lea, J. T., Watkins, D., Mills, A., Peshkin, M. A., Kienzle III, T. C., Stulberg, D. S.: “Registration and Immobilization for Robot-Assisted Orthopaedic Surgery,” Proceedings of the First International Symposium on Medical Robotics and Computer Assisted Surgery, Volume I, Sessions I-III, Pages 63-68, Pittsburgh, Pa., Sep. 22-24, 1995. (16) Ault, T., Siegel, M. W.: “Frameless Patient Registration Using Ultrasonic Imaging,” Proceedings of the First International Symposium on Medical Robotics and Computer Assisted Surgery, Volume I, Sessions I-III, Pages 74-81, Pittsburgh, Pa., Sep. 22-24, 1995. (17) Champleboux, G., Lavallee, S., Cinquin, P.: “An Optical Conformer for Radiotherapy Treatment Planning,” Proceedings of the First International Symposium on Medical Robotics and Computer Assisted Surgery, Volume I, Sessions I-III, Pages 69-73, Pittsburgh, Pa., Sep. 22-24, 1995.
Various systems for image registration using fiducial implants are also described in U.S. Pat. Nos. 4,991,579; 4,945,914; 5,094,241; 5,119,817; 5,097,839; 5,142,930; 5,211,164; 5,230,338; 5,222,499; and 5,397,329 to Allen.
A system and method for performing robotically assisted surgery is described in U.S. Pat. No. 5,086,401. Computer-assisted imaging and probe tracking systems are described in U.S. Pat. Nos. 5,383,454; 5,198,877; and WO 91/07726. Copending and recently allowed application Ser. No. 08/526,826, assigned to the assignee of the present application, describes a method and system for transforming a bone image into a robotic coordinate system by aligning a robotic probe within the medullary canal of the femur. Patent application Ser. No. 09/022,643, also assigned to the assignee of the present application, describes a method and system for transforming a bone image into a robotic coordinate system based upon registering between the robotic coordinate system and the image data set 1) two positional coordinates axially spaced apart along the bone and 2) a directional vector passing through at least one of the positional coordinates.
Thus, there is a need for an improved system and method for a counterbalanced surgical robotic system using an actuator that is both precise enough for accurate cutting, and strong enough to handle the moment load of the cantilevered robot arm, with a range of motion sufficient to increase overall workspace compared to existing robotic arms. In addition, in some instances it is important to minimize the size and weight of the robot base, as well as reducing the overall weight of the arm. This invention provides such a new and useful system and method.